Garmin inReach Flash Memory Analysis

Iridium Short Burst Data (SBD) Satellite Communicator - Serial NAND/NOR Disruption Assessment

Garmin inReach Satellite Communicator
Garmin inReach - Handheld Satellite Communicator
Garmin inReach Device View 2
Rugged outdoor design for remote communication

What is Iridium Short Burst Data (SBD)?

The Garmin inReach uses Iridium's Short Burst Data (SBD) service for two-way satellite messaging anywhere on Earth. Unlike voice satellite phones, SBD transmits small data packets (up to 340 bytes outbound, 270 bytes inbound) through Iridium's 66-satellite constellation.

This enables GPS tracking, SOS emergency alerts, and text messaging in locations with zero cellular coverage—critical for hikers, sailors, pilots, and remote workers. The flash memory stores firmware, maps, message queues, and GPS waypoints.

66
Iridium Satellites
100%
Earth Coverage
340B
Max Message Size
-20°C
Operating Temp

PCB Teardown Analysis - Flash Memory Configurations

Garmin inReach PCB with MXIC Parallel NOR

PARALLEL NOR Design Variant A

This board revision uses Macronix parallel NOR flash for code storage and XIP (execute-in-place) operation.

Flash Part MX29L (Macronix)
Interface Parallel (48+ pins)
Type NOR Flash
Primary Use Firmware / XIP Boot
Package TSOP-48

Parallel NOR provides fastest random access for code execution but requires significant PCB routing and larger package.

Garmin inReach PCB with Spansion Serial Flash

SERIAL FLASH Design Variant B

This board revision transitioned to Spansion serial flash—demonstrating the parallel-to-serial migration already happening.

Flash Part Spansion Serial
Interface SPI/QSPI (8 pins)
Type Serial NOR/NAND
Primary Use Firmware + Data
Package SOIC-8 / WSON-8

Serial interface dramatically simplifies PCB layout. Smaller package enables more compact product design.

Attribute Parallel NOR (MX29L) Serial Flash (Spansion)
Pin Count 48+ pins 8 pins
PCB Layers Requires more layers Simpler routing
Package Size TSOP-48 (larger) SOIC-8 (6x smaller)
XIP Support Native XIP Requires shadow RAM or XIP controller
Random Read Speed Faster random access Sequential optimized
Cost Trend Premium pricing Aggressive cost reduction
Supply Chain Fewer suppliers Multiple sources

Serial NAND/NOR Disruption Potential

⚡ Serial NOR Opportunity

  • Garmin already migrated some SKUs to serial flash
  • Proof that parallel NOR is not technically required
  • Modern MCUs have QSPI controllers with XIP support
  • Spansion/Infineon, Winbond, MXIC all have serial NOR
  • Density requirements (16-128Mb) fit serial NOR sweet spot
DISRUPTION IN PROGRESS - Serial NOR already winning designs

🔥 Serial NAND Opportunity

  • Higher densities (1-8Gb) at lower cost than NOR
  • Ideal for map data, message logs, GPS tracks
  • Can pair with small serial NOR for boot code
  • ECC handled by controller—transparent to system
  • Growing ecosystem: Micron, Winbond, MXIC, Toshiba
HIGH POTENTIAL - Data storage expansion opportunity
Key Insight: The Migration Is Already Happening The existence of two inReach board variants—one with parallel NOR, one with serial flash—proves Garmin is actively transitioning away from parallel interfaces. This pattern will accelerate across the entire satellite communicator and rugged GPS market. Serial NAND can capture the growing data storage needs (larger maps, more waypoints, firmware OTA) while serial NOR handles boot-critical code.

Similar Applications Ripe for Serial Flash Disruption

Satellite Communicators

SPOT, Somewear, Bivy Stick, Zoleo—all use similar architectures with Iridium/Globalstar modems

Aviation GPS/EFBs

Garmin aviation, ForeFlight hardware—need reliable flash for terrain/obstacle databases

Marine Electronics

Chartplotters, fishfinders, AIS transponders—similar rugged/reliable requirements